array_reduce

array_reduce

Iteratively reduce the array to a single value using a callback function

mixed **array_reduce** array $array callable $callback mixed $initial

applies iteratively the
function to the elements of the

, so as to reduce the array to a single value. array_reduce``callback``array

arrayThe input array.

`callback````php mixed **** mixed $carry mixed $item

`carry`
          Holds the return value of the previous iteration; in the case of the
          first iteration it instead holds the value of 
          .
         `initial`

`item`Holds the value of the current iteration.

`initial`
       If the optional  is available, it will
       be used at the beginning of the process, or as a final result in case
       the array is empty.
      `initial`



Returns the resulting value.


   If the array is empty and  is not passed,
    returns null.
  `initial``array_reduce`


   
  **Voorbeeld:  example**

```php
<?php
function sum($carry, $item)
{
    $carry += $item;
    return $carry;
}

function product($carry, $item)
{
    $carry *= $item;
    return $carry;
}

$a = array(1, 2, 3, 4, 5);
$x = array();

var_dump(array_reduce($a, "sum")); // int(15)
var_dump(array_reduce($a, "product", 10)); // int(1200), because: 10*1*2*3*4*5
var_dump(array_reduce($x, "sum", "No data to reduce")); // string(17) "No data to reduce"
?>

array_filter``array_map``array_unique``array_count_values